Definition

MEV

Maximal Extractable Value — profit a block proposer or specialist searcher can extract by reordering, including, or censoring transactions within a block.

When a transaction is broadcast to the mempool, anyone watching can see it before it's confirmed. Searchers (specialized bots) scan the mempool for profitable opportunities: an arbitrage between two DEX prices, a liquidatable lending position, or a user's swap they can sandwich (front-run + back-run).

The most common MEV strategies: arbitrage (legitimate, prices align), liquidations (legitimate, lending protocols reward this), sandwich attacks (extracts value from retail swaps via slippage abuse), and JIT liquidity (provide liquidity for one block to capture fees on a known incoming swap).

MEV has become a multi-billion-dollar economy. Flashbots and similar relays let searchers submit private transaction bundles directly to validators, bypassing the public mempool. Flashbots alone has settled tens of billions in MEV-extracted volume since launch.

Why it matters

MEV is a tax retail traders pay invisibly. A $10K Uniswap swap can lose $50-$500 to sandwich attacks unless protected by MEV-resistant routing.

How CryptoRadar24 tracks it

CryptoRadar24 covers MEV when reporting on DeFi structural risks; we don't produce live MEV stats but reference Flashbots data when relevant.

Related terms

Gas fee
Transaction fee paid to network validators on Ethereum and similar blockchains, denominated in the chain's native token.
Slippage
Difference between the expected price of a trade and the price at which it is actually executed.
AMM
Automated market maker that uses liquidity pools instead of order books.

FAQ

Is MEV always bad?

Arbitrage and liquidations keep markets efficient — those are net-positive. Sandwich attacks and "toxic" MEV degrade the user experience and effectively tax retail traders.

How do I avoid MEV?

Use private RPCs (Flashbots Protect, MEVBlocker), set tight slippage tolerance, use aggregators that route through MEV-protected paths, or trade on L2s where mempools are less public.

Who captures MEV today?

Searchers (~80%), validators (~15%), and the relayer infrastructure operators (~5%). Pre-Merge it was miners and bots; post-Merge it shifted toward validators via mev-boost.

Does MEV exist on Bitcoin?

Far less. Bitcoin transactions are simpler (no smart contracts), so the only meaningful MEV is fee-priority manipulation. The big MEV economy is Ethereum and EVM L2s.